Conventionally, a spatial diversity technique for reducing degradation of transmission characteristics due to fading in wireless communications has been known. A transmission device includes two antennas, where a modulated wave is transmitted from one antenna and a modulated wave delayed by one time slot or more is transmitted from the other antenna. A receiving device performs multipath processing of emphasizing and extracting a principal wave component included in a reception wave. With this configuration, it is possible to obtain a diversity effect by spatial and frequency diversity without broadening bandwidths. Such a technique is disclosed in Patent Literature 1 mentioned below.